Marble Gate

Inspired by Wintergatan I designed, 3D-printed and built this Pac-Man Marble Gate.

I obviously got the idea for the gate from the Wintergatan videos (here is a live stream where Martin designs the gates for the Cyberbass), but I created the 3D design for this project from scratch in Fusion 360.

The gate works like a marble dispenser. If you push the lever at the bottom, it will turn the gears, causing the Pac-Man to release a single marble through the base. The mechanism is reset by the counter weight on the left. Check out the video below.

Most of the parts are 3D printed (on an Anycubic Photon Mono). The axles are made from coat hanger wire, which is a trick I learned from Adam Savage. The counter weight is a weird metal part, which I have used as a weight in another project as well. I ordered a set of these explicitly to use as weights, so I forgot their intended application. A marble is attached to the counter weight using hot glue for additional weight. All the other parts are glued to the axles using regular glue. I ordered metal marbles in the same size as used by Wintergatan (actually 15.875mm steel bearing balls).

Assembly required only minimal modification of the 3D printed parts. Mainly the gears were a fraction of a millimeter too big, which was fixed with a little sandpaper, and the holes were (intentionally) too small and were drilled bigger to achieve a tight fit on the axles.

In principle the design works, however, the marbles are a lot heavier than I expected and dropping them from the top would probably rip the whole thing apart, so the device has to be loaded a little more carefully. The weakest point is the connection between the parts and the axles and I had to reglue a few parts just to film the video.

Also, the static pressure from the marbles is quite high and almost able to overcome the counter force from the weight. A design where the top section is at an angle would be much better.

Finally, I should have built a tray to catch the marbles, as they are currently ejected from the base, shooting directly for the edge of your table and marbles make a horrible sound when they hit the floor.

Posted in DIY